TGK Ultimate Billet Coolant Kit For Audi 4.0T

Address all three of the front coolant components in the Audi 4.0T cooling system with the TGK Motorsport Ultimate Coolant Reliability Bundle — featuring our Billet Front Thermostat Piping Kit, Coolant Shutoff Valve Delete Kit, and Billet Coolant Flange. This comprehensive upgrade replaces all factory plastic fittings with 6061-T6 billet aluminum components and introduces critical sealing improvements to eliminate coolant leaks and overheating risks once and for all.

The Audi 4.0T engine’s cooling system is plagued by multiple weak points that commonly result in hard-to-diagnose coolant leaks, vacuum-related failures, and even engine-threatening overheating. Each of these components is vulnerable due to the OEM use of plastic housings and minimal sealing — and all three are known to fail, often at the worst time.

This all-in-one kit provides a permanent solution by replacing the front thermostat elbow, coolant shutoff valve, and main coolant flange with precision-machined billet aluminum parts designed for performance, reliability, and peace of mind.

Front Thermostat Billet Piping Kit
At the front of the thermostat housing, Audi uses a plastic coolant elbow sealed with a single O-ring. Over time, especially in cold temperatures, this O-ring can shrink or harden, causing subtle but persistent coolant leaks. The plastic body itself can also deform from engine heat, compounding the issue.

The TGK Motorsport Billet Elbow is machined from 6061-T6 aluminum and designed with a dual-gasket sealing system for enhanced redundancy and leak prevention. This upgrade ensures long-term durability, even in cold starts and under high-pressure conditions.

Coolant Shutoff Valve Delete Kit
Audi equips the 4.0T with a vacuum-actuated coolant shutoff valve that blocks flow at cold start to speed up warm-up time. However, this valve is known to fail in the closed position, preventing coolant circulation and significantly increasing the risk of overheating.

The TGK Motorsport Delete Kit removes this complex and failure-prone component completely. By restoring continuous coolant flow and simplifying the coolant path, the delete kit improves reliability and eliminates one of the most dangerous hidden failure points in the system.

Billet Coolant Flange
The factory coolant flange, another plastic component under constant thermal and pressure stress, can develop cracks and leaks over time — especially in higher-mileage or tuned vehicles. This component is a known source of hidden coolant loss and long-term system degradation.

Our Billet Coolant Flange is CNC-machined from 6061-T6 aluminum, offering significantly greater strength, heat resistance, and longevity. This direct-fit replacement eliminates warping, cracking, and leaks, ensuring a secure seal and long service life.

Why Bundle All Three?
Each of these cooling system components is a known failure point on the Audi 4.0T — and they often fail silently. By upgrading all three at once, the TGK Motorsport Ultimate Coolant Kit provides a complete and permanent solution, whether you're chasing down a mystery coolant leak or proactively upgrading for peace of mind.

This bundle is ideal for preventative maintenance, engine builds, or any owner looking to bulletproof their 4.0T cooling system with OEM+ fitment and motorsport-grade reliability.